It has happened to all of us at sometime or the other. We may have lost contact with a friend or family member and suddenly something reminds us of them and we want to get back in touch with that person. The fastest and easiest way to contact someone these days is by email. Or maybe you need to send some very important documentation and have lost the email address. It could be that you are getting a lot of anonymous emails and are trying to find out who it is coming from.